Dementors
by WhenTheSkyFallsI'llHoldItUp
Summary: Percy and Nico are sent to Hogwarts School of Witchcraft and Wizardry by Hecate to research on dementors, and the task seems simple enough at first since the castle is surrounded by them. However, when Sirius Black breaks into the castle, they must find out the flaw in dementors and make a decision - Fix the flaw and help Hecate, or help Sirius and become her enemy.
1. Chapter 1

**A/N: I know there are a lot of stories out there about demigods going to Hogwarts, and this story starts out pretty much the same way as a lot of them. Hopefully, things will get more interesting in the future chapters.**

 **Disclaimer: I do not own Percy Jackson and the Olympians, or Harry Potter, to my great sorrow.**

"So I suppose you know why you're here, Peter Johnson?" Dionysus asked lazily, taking a big swig from his can of Diet Coke.

"Not really," I replied, exchanging a confused look with Nico who had been summoned there with me.

"I'll explain," said Chiron hastily, moving forward. "The thing is, Hecate wants you two to research on a certain... monster, of a sort. It's called a dementor, and apparently, it's a magical creature, so she's sending you two to a magic school in Scotland to study it."

My mind began to form more questions, and I couldn't decide which one to ask. There was a long silence.

"Why us?" Nico finally asked, breaking the silence. For a moment he looked rather nervous, but his face instantly changed into an emotionless mask. I stared at him for a moment, and then shifted my gaze to Chiron.

"We wanted the children of the big three to complete the quest," he said simply. "Jason and Hazel don't count because they're Roman, but we might have to send them as well if you seem to have a hard time researching. And Thalia doesn't count either because she's a Hunter of Artemis now, and she is under the guardianship of Artemis."

"In other words, we wanted to get rid of the most annoying demigods at camp and decided to start with you," Dionysus added.

"We don't know any magic, though," I said. The last thing I wanted was to go on this quest, and then either expose the fact I was a demigod or make a fool of myself when we were supposed to perform actual magic.

"Hecate has taken care of that. You can perform magic when on the quest, and she will remove the magic when the quest is over. You just need to learn a few spells, which you can learn at the school. Meanwhile, you need wands." Chiron pulled out two narrow, wooden boxes, and handed one each to me and Nico.

"Percy, yours is made of apple wood, with phoenix tail feather core, eleven and a half inches long. Nico, yours is acacia with threstal hair, nine and three-quarters inches long," Chiron said, referring to the long stick things inside the boxes. "They say 'the wand chooses the wizard', but we never tried it with demigods, and since we've tried to find wands that match your personalities as closely as possible, it's unlikely anything will go wrong."

"Wizard?" I asked, surprised, (of course, that would be the only thing that would stick to my mind.) "You mean people wearing long robes and pointy hats and long beards?" I hoped I was wrong because I didn't really want to grow a long white beard at the age of seventeen.

"Well," Chiron said hesitantly, "You've given a very accurate description of the headmaster of the school. You'll have to wear the... ah... 'pointy hats' and long robes to school, though."

"And why do we need to go to a school in Scotland to study this demon-whatever-it-is?" I asked. I felt rather frustrated, being sent on a quest immediately after I had fulfilled two Great Prophecies.

"You'll see," Chiron said mysteriously, winking at me. There was another long silence.

"When do we leave?" Nico asked suddenly. He really did seem nervous, I wondered why.

"Right now," Chiron replied. "One more thing - only the headmaster, Albus Dumbledore knows that you are demigods. Please try to keep it that way. If any problem occurs, or if anyone finds out, IM me as soon as possible." He tossed a small bag of drachmas at Nico, which he caught. "You can leave now."

The next thing I knew, Nico grabbed my arm and we were traveling through the shadows.

 **Please review! Your reviews help me improve my writing. I'll try to write longer chapters in the future.**


	2. Chapter 2

**A/N: I know I haven't updated for months. After the first chapter, I decided I couldn't continue it because it was way too much responsibility. But even after I chose to abandon it, the reviews kept coming so I thought - okay, I can do this. I won't abandon this - someday, it shall be complete.**

 **Disclaimer: I do not own PJO or Harry Potter.**

Travelling through shadows might sound like great fun, but trust me, it's not.

Well, Nico seems to enjoy Shadow Travel (as far as I can tell), so I suppose it depends on whether you like travelling so fast it feels like your skin is peeling off. So you can't blame me for feeling relieved when we finally reached our destination - until I saw the black, hooded figures surrounding me.

I felt cold, and a bad feeling washed over me - a feeling of dread, the way I felt as I stood at the edge of Tartarus, a slightly milder version of the feeling I had as I stood at the edge of Chaos. One figure glided forward, and I tried to step back but tripped over my shoelaces. The figure slowly raised it's hood, and I closed my eyes, expecting something like Medusa's face as the face of these creatures, hoping they couldn't hurt me if I didn't look at them.

But then I felt my worst memories flash before my eyes - my mother kidnapped by Hades, my friends dying - Zoe, Bianca, Bob, Beckendorf - watching Annabeth get dragged into Tartarus, stuck in Tartarus with Annabeth - and suddenly the flashbacks stopped. I opened my eyes a fraction and saw silver light as I passed out.

Before I even opened my eyes, I heard voices around me.

"Poppy, do you have any idea what these two boys were doing outside the gates?"

"I told you, Minerva, I have no idea. Perhaps they are muggles, and thought it would be fun to explore a ruined castle... but the dementors should have scared them off, even if they couldn't see them."

"And they have wands-"

"Yet Ollivander claims he never saw these two in his life, and it's certain Ollivander made these wands."

"If they were wizards, we'd know, wouldn't we? Even if they rejected their letter... but the wands..."

I opened my eyes, and the first thing I saw was white - white walls, white curtains surrounding white beds like the one I was lying on. This was some kind of hospital or infirmary, I guessed. Two women stood between my bed and another one, where Nico was still lying unconscious, one evidently a nurse and the other wearing green robes and a pointy hat. Both stared at me as I yawned and stared right back at them. "What?"

The nurse looked amused as if she wanted to tell me I drooled in my sleep. I get that a lot, especially from Annabeth or whoever walks in on me when I'm sleeping. "I'm Poppy Pomfrey," she said instead. "Who are you?"

I remembered Chiron told me not to tell anyone that I was a demigod, and if I told them my name the next question they would ask would be why I was here. It would be better to hesitate at the first question rather than the second, so I paused and raised my eyebrows at the other woman, hoping to buy time.

"I'm Professor McGonagall," the woman said, then raised her eyebrows right back at me. "Why are you here?"

I wondered what to tell her. I wished Chiron had told me what to say and wished Nico was awake. My wish came true - the second one at least, as Nico opened his eyes and rolled over, his eyes landing on me and then at the women. "Ask him," I replied to the professor, and Nico's eyes widened. "What?"

After looking at me oddly, the professor repeated her question to Nico, who relaxed. "Professor Dumbledore expects us," he said simply, and the two women looked at each other, seemingly accepting it. I got the idea that whoever Professor Dumbledore was, he could do anything no matter how weird and get away from it, by their reaction. The professor left the room, and the nurse followed. Nico and I were alone in the room, and there was an uncomfortable silence.

"Um," I said, "you seem to know this place pretty well." Annabeth may think I have seaweed for brains, but it was pretty obvious Nico had been here before.

"No I don't!" he said defensively. "I just happen to know how to act in situations where my motives are doubted."

"You knew where to shadow travel."

"I... just shadow travelled without thinking and the gods guided me."

I didn't believe him, but I let the subject drop, and we waited for the professor to return without speaking.

It seemed like hours before Professor McGonagall returned, and behind her was a man with dark blue robes and a long white beard. I assumed he was Professor Dumbledore. He smiled at us.

"Minerva," he said, turning to Professor McGonagall, "this is Perseus Jackson, and this is Nico di Angelo. Perseus is sixteen years old -" I opened my mouth to say I was seventeen, but he silenced me with a look - "and Nico di Angelo is fourteen. They will be joining Hogwarts, I'd prefer if no questions were asked." Professor McGonagall nodded. "If Poppy believes they have recovered enough, you may take them to be sorted with the first years."

Madam Pomfrey entered the room - she had been standing by the doorway, I hadn't noticed. She took out her wand and waved it in our direction once, then nodded. "You may take them, Minerva. The students will arrive soon." Nico and I climbed out of our beds and started to follow Professor McGonagall, but I stopped halfway to the doorway.

"Sir?" I said, turning to Professor Dumbledore. He looked at me, a twinkle in his eye. "What were the monsters we saw... before we got here?"

He smiled. "They are called 'Dementors'," he replied, and Nico grabbed my arm and guided me through the door but I was too lost in my thoughts to notice where we went - I had assumed that when Chiron told us we would go to a magic school in Scotland to study dementors, I assumed we would study them in books - I shuddered at the thought of having to get close to those creatures again to study them, but I pushed the thought out of my mind. Right now, I had to concentrate on pretending to be a normal wizard, and complete this quest as quickly as possible so I could finally go home.


End file.
